/*@internal*/
namespace ts {
    export enum UpToDateStatusType {
        Unbuildable,
        UpToDate,
        /**
         * The project appears out of date because its upstream inputs are newer than its outputs,
         * but all of its outputs are actually newer than the previous identical outputs of its (.d.ts) inputs.
         * This means we can Pseudo-build (just touch timestamps), as if we had actually built this project.
         */
        UpToDateWithUpstreamTypes,
        /**
         * The project appears out of date because its upstream inputs are newer than its outputs,
         * but all of its outputs are actually newer than the previous identical outputs of its (.d.ts) inputs.
         * This means we can Pseudo-build (just manipulate outputs), as if we had actually built this project.
         */
        OutOfDateWithPrepend,
        OutputMissing,
        OutOfDateWithSelf,
        OutOfDateWithUpstream,
        UpstreamOutOfDate,
        UpstreamBlocked,
        ComputingUpstream,
        TsVersionOutputOfDate,

        /**
         * Projects with no outputs (i.e. "solution" files)
         */
        ContainerOnly
    }

    export type UpToDateStatus =
        | Status.Unbuildable
        | Status.UpToDate
        | Status.OutOfDateWithPrepend
        | Status.OutputMissing
        | Status.OutOfDateWithSelf
        | Status.OutOfDateWithUpstream
        | Status.UpstreamOutOfDate
        | Status.UpstreamBlocked
        | Status.ComputingUpstream
        | Status.TsVersionOutOfDate
        | Status.ContainerOnly;

    export namespace Status {
        /**
         * The project can't be built at all in its current state. For example,
         * its config file cannot be parsed, or it has a syntax error or missing file
         */
        export interface Unbuildable {
            type: UpToDateStatusType.Unbuildable;
            reason: string;
        }

        /**
         * This project doesn't have any outputs, so "is it up to date" is a meaningless question.
         */
        export interface ContainerOnly {
            type: UpToDateStatusType.ContainerOnly;
        }

        /**
         * The project is up to date with respect to its inputs.
         * We track what the newest input file is.
         */
        export interface UpToDate {
            type: UpToDateStatusType.UpToDate | UpToDateStatusType.UpToDateWithUpstreamTypes;
            newestInputFileTime?: Date;
            newestInputFileName?: string;
            newestDeclarationFileContentChangedTime?: Date;
            newestOutputFileTime?: Date;
            newestOutputFileName?: string;
            oldestOutputFileName: string;
        }

        /**
         * The project is up to date with respect to its inputs except for prepend output changed (no declaration file change in prepend).
         */
        export interface OutOfDateWithPrepend {
            type: UpToDateStatusType.OutOfDateWithPrepend;
            outOfDateOutputFileName: string;
            newerProjectName: string;
        }

        /**
         * One or more of the outputs of the project does not exist.
         */
        export interface OutputMissing {
            type: UpToDateStatusType.OutputMissing;
            /**
             * The name of the first output file that didn't exist
             */
            missingOutputFileName: string;
        }

        /**
         * One or more of the project's outputs is older than its newest input.
         */
        export interface OutOfDateWithSelf {
            type: UpToDateStatusType.OutOfDateWithSelf;
            outOfDateOutputFileName: string;
            newerInputFileName: string;
        }

        /**
         * This project depends on an out-of-date project, so shouldn't be built yet
         */
        export interface UpstreamOutOfDate {
            type: UpToDateStatusType.UpstreamOutOfDate;
            upstreamProjectName: string;
        }

        /**
         * This project depends an upstream project with build errors
         */
        export interface UpstreamBlocked {
            type: UpToDateStatusType.UpstreamBlocked;
            upstreamProjectName: string;
            upstreamProjectBlocked: boolean;
        }

        /**
         *  Computing status of upstream projects referenced
         */
        export interface ComputingUpstream {
            type: UpToDateStatusType.ComputingUpstream;
        }

        export interface TsVersionOutOfDate {
            type: UpToDateStatusType.TsVersionOutputOfDate;
            version: string;
        }

        /**
         * One or more of the project's outputs is older than the newest output of
         * an upstream project.
         */
        export interface OutOfDateWithUpstream {
            type: UpToDateStatusType.OutOfDateWithUpstream;
            outOfDateOutputFileName: string;
            newerProjectName: string;
        }
    }

    export function resolveConfigFileProjectName(project: string): ResolvedConfigFileName {
        if (fileExtensionIs(project, Extension.Json)) {
            return project as ResolvedConfigFileName;
        }

        return combinePaths(project, "tsconfig.json") as ResolvedConfigFileName;
    }
}